System and method for sensor recalibration
A system and method for calibrating a sensor. The method may include, without limitation, compiling an array of data relating to the sensor; adjusting a sensor parameter a first time based on data in the array; adjusting a curve representing the sensor output based on data in the array; and adjusting the sensor parameter a second time based on data in the array. The sensor may be an in vivo glucose sensor and the sensor parameter adjusted may be a current. The array may include historical as well as recent data, such as, for example, blood glucose readings and sensor electrode readings.
1. A method for adjusting a calibrating curve for a sensor calibration comprising:
compiling a calibration array of data values relating to the sensor;
generating a calibration curve;
adjusting a nominal output current of the sensor based on data in the calibration array;
adjusting the calibration curve based on the adjusted value of the nominal output current;
wherein adjusting the calibration curve representing the sensor output further comprises performing a linear regression on data in the calibration array; and
wherein a result of the linear regression determines a first calibration point.
2. The method of claim 1 , wherein compiling the calibration array comprises compiling historical data.
3. The method of claim 2 , wherein the historical data comprises measured blood glucose readings.
4. The method of claim 1 , wherein compiling the calibration array comprises compiling recent data.
5. The method of claim 4 , wherein the recent data comprises electrode readings.
6. The method of claim 5 , wherein the electrode readings comprise glucose electrode readings and oxygen electrode readings.
7. The method of claim 4 , wherein the recent data comprises measured blood glucose concentrations.
8. The method of claim 7 , wherein the nominal output current is a nominal glucose current.
9. The method of claim 8 , wherein the nominal glucose current is adjusted based on a shift of measured data points with respect to blood glucose readings.
10. The method of claim 9 , wherein the shift is a mean shift.
11. The method of claim 1 , wherein the first calibration point is used to determine a plurality of calibration points.
12. The method of claim 1 , wherein adjusting the calibration curve representing the sensor output comprises adjusting the calibration curve in a piecewise linear fashion.
13. The method of claim 12 , wherein a number of pieces in the piecewise linear adjustment is five.
14. The method of claim 1 , further comprising compiling a second calibration array of data values relating to the sensor; adjusting the nominal output current of the sensor a second time based on data in the second calibration array.
15. The method of claim 14 , wherein the nominal output current is a nominal glucose current.
16. The method of claim 15 , wherein the nominal glucose current is adjusted based on a shift of measured data points with respect to blood glucose readings.
17. The method of claim 16 , wherein the shift is a mean shift.
18. The method of claim 1 , further comprising establishing a new sensor output based on the adjusted calibration curve and the twice adjusted nominal output current.
19. The method of claim 1 , wherein generating a calibration curve comprises generating a calibration curve based on a priori empirical values, and wherein the method further comprises:
compiling a plurality of data values from the sensor;
compiling independent historical values of a parameter sensed by the sensor; and
reconciling the plurality of data values from the sensor to the calibration curve using the independent historical values.
20. The method of claim 19 , wherein the sensor is a glucose sensor.
21. The method of claim 19 , wherein generating a calibration curve comprises compiling a priori empirical values of sensors similar to the sensor being calibrated.
22. The method of claim 19 , wherein generating a calibration curve comprises generating a calibration curve representing a sensor having a plurality of phases.
23. The method of claim 19 , wherein the independent historical values of a parameter sensed by the sensor are metered blood glucose values.
24. The method of claim 19 , wherein reconciling the plurality of data values comprises adjusting an output current of the sensor.
25. The method of claim 24 , wherein the output current of the sensor is a nominal glucose current.
26. The method of claim 25 , wherein the nominal glucose current is adjusted based on a shift of the plurality of data values from the sensor with respect to metered blood glucose values.
27. The method of claim 19 , wherein reconciling the plurality of data values comprises performing a linear regression on the plurality of data values.
28. The method of claim 19 , wherein reconciling the plurality of data values is performed in a piecewise linear fashion.